Windows 11 KB5089549 Install Bug Blocks Security Updates on Low-ESP Systems

Microsoft confirmed that the mandatory Windows 11 cumulative update KB5089549 is failing on some devices, leaving them without the latest security fixes. The installation issue is primarily affecting systems with nearly full EFI System Partitions (ESP)—especially those with about 10 MB or less of free space—and commonly triggers errors including 0x800f0922, 0x80240069, and 0x80240031. Affected machines often stall at roughly 35–36% during restart, then roll back the update instead of completing installation.

Microsoft said it deployed a server-side Known Issue Rollback (KIR) to mitigate the problem for consumer and unmanaged business devices, with the fix expected to apply automatically after a restart. The company also advised users to reboot and retry the update, while enterprise administrators were told to use a Group Policy mitigation for managed environments. Reports also noted that some impacted systems experienced boot issues or degraded performance, adding to broader concerns over recent Windows update reliability problems.